Efficient test bitstream generation with an N-way covering algorithm for configurations of high-level syntax elements in video decoders

Test bitstreams are more efficient in testing the video decoders if its bitstream length is shorter while its test coverage is higher. In this paper, a new method to generate efficient bitstreams for functional tests of video decoders is proposed, which also can find and fill up coverage holes. The proposed method employs an n-way covering combinatorial algorithm in finding an efficient configuration set of high-level syntax elements (SEs) and uses a constrained-random algorithm in generating test cases for low-level SEs. With the test bitstreams for MPEG-4 and H.264 decoders generated with the proposed method the experimental results showed that the proposed method is more efficient than the conventional methods. It also showed that the average SE coverage of the generated bitstream set can easily be improved by filling up coverage holes with the proposed method.